The purpose of the present proposal is to develop and describe syngeneic (isogenic) strains of rainbow trout as a lower vertebrate aquatic animal model for biomedical research. In particular, we will develop these fish for the study of immunological phenomena. These trout will be useful not only for immunological research such as immunogenetics and neuroimmunology, but will fill many niches in such diverse areas as endocrinology, developmental biology, aquatic toxicology, gene transfer technology and carcinogenesis research. The specific aims of the project are the propagation of existing and development of new isogenic lines by androgenesis and gynogenesis, validation of the isogenic nature of the derived fish; and further development of immunological techniques using the trout as models.